Further analysis of the ATP-binding cassette transporters (ABC) gene family revealed that multiple ABC genes implicated in AML relapse and chemoresistance39 were up-regulated in chemoresistant Doxo ± Cyta groups compared to Doxo + Cyta + DAC, particularly ABCC3, A2 and B6 (Fig. 4h). Here, ABCA4 is linked to acute myeloid leukemia.